Originally, an exit sign used standard incandescent lamps. The earliest alternatives to incandescent lamps were radioactive tritium gas and compact fluorescent lamps. In 1985, light-emitting diodes (LEDs) were introduced for use in exit signs.
The most cost-effective alternative today over the exit signs that use incandescent lamps are LED exit signs. A standard LED exit sign generally uses only about 1 to 5 watts of power per surface and costs less than $5.00 per year to operate depending on the model and local utility costs. Because LEDs also last considerably longer than incandescent lamps, life cycle savings are dramatic. When an LED exit sign is used instead of an incandescent exit sign, the cost saving multiple over a ten-year period including initial costs, energy expenditures, and maintenance requirements will be in the range of five times.
There are currently several different types of LED exit signs available in the marketplace using a variety of LEDs in different configurations. There are a great number of LED sign manufacturers competing in the market. As a result, there is a wide range in price, quality, and energy consumption. Some LED signs use as few as 6 LEDs, others use 18 to 35 LEDs, and some use up to 200 LEDs. The rated energy consumption can thus range from as little as 1 watt up to 8 watts.
Under National Fire Protection Association (NFPA), National Electrical Code (NEC), Underwriters Laboratories (UL) and local fire and building codes for each state, buildings that provide public access are required by law to have signs therein identifying the exits. These emergency signs are required to exhibit a specific amount of illumination and often times are required to have an emergency backup power source to provide emergency illumination to the exit sign for a specified period of time when electrical power to the building is interrupted to allow sufficient time for persons in the building to vacate. LED exit signs are presently available primarily with red or green color LEDs, or other approved colors as required by local ordinances or municipalities and depending on state and city codes.
No LED exit sign presently exists that is commercially manufactured to the best of my knowledge that provides a choice of either red or green color LEDs along with a switch to select the color of the exit sign indicia that is legally required by the particular jurisdiction. In the selective color LED lamp of the present invention, the switch can selectively turn on the red color LEDs to produce a red color exit sign indicia, or selectively turn on the green color LEDs to produce a green color exit sign indicia. In addition, the LED lamp of the present invention can selectively turn on both the red and green color LEDs simultaneously to produce a yellow color exit sign indicia. Exit signs usually include a stencil having perforations that define indicia through which the LED light passes and which is readable by an observer. Existing stencil signs have solid colored green or red diffuser panels behind opaque sections with the letters EXIT cut out. Other exit signs can include a stencil manufactured out of a clear lens with the indicia or background masked with a red, green, or other color ink. The word EXIT is usually white in this case against the color background. The indicia generally form the letters of the word EXIT and include removable or permanent chevron arrows located on opposite sides of the word EXIT. Other words, symbols, or idiogram indicia can indicate an exit. Among these are words or symbols in non-English speaking countries that have an analogous meaning to the word EXIT in English.
The present invention provides an LED lamp that enables a user to selectively, or optionally, produce distinct color outputs. The selective color LED lamp is designed for use in illuminated signs generally including emergency exit signs, but also other types of illuminated signs that can be used in different locations. The use of the selective color LED lamp will allow the emergency signage to comply with all local fire and building code requirements. An LED exit sign manufacturer, wholesaler, and retailer can stock only one basic version of the selective color LED lamp exit sign thereby reducing manufacturing, inventory, and shipping costs. The selective color LED lamp is designed to replace existing incandescent and single color LED lamps. It can be used directly in sockets of existing emergency exit signs as retrofit LED lamps, or as the main light source in new emergency exit signs and other illuminated signs. Besides using the selective color LED lamp of the present invention in emergency exit signs, the selective color LED lamp can be used in illuminated advisory, directional, instructional, warning, and safety demarcation signs. In the latter uses, other selective colors can be used other than the red, green, and yellow colors of the selective color LED lamp. Another area where the selective color LED lamp of the present invention can be used is in warning and instructional lighting markers used in many truck-loading docks around the country.
It is an object of the present invention to provide a selective color LED lamp wherein one of the color red or the color green can be selected for general signage lighting applications incorporating light emitting diodes as the main light source for use in existing and newly manufactured signage lighting fixtures.
Another object of the present invention is to provide such a selective color LED lamp that can readily replace the incandescent and compact fluorescent lighting units offering energy efficiency, longer life with zero mercury, zero disposal costs, and zero hazardous waste. The present invention can be used with all types of illuminated signage.
Yet another object of the present invention is to provide a selective color LED lamp that will easily produce a red color or green color while substantially using a low number of color LEDs wherein such use is in the field of emergency exit signs.
Yet another object of the present invention is to provide a selective color LED lamp that will easily produce a red color or green color or a mixed red and green color to produce the color yellow while using a relatively low number of colored LEDs wherein such use is in the field of emergency exit signs.
A further object of the present invention is to provide a selective color LED retrofit lamp containing integral electronic circuitry that can be readily and economically fabricated from simple electronic components for easy adaptation for use with existing illuminated signage.
And yet a further object of the present invention is to provide a selective color LED lamp combined with surge suppression, uniform illumination, battery backup, and low power consumption to be readily and economically fabricated from simple components, for use in newly manufactured and multipurpose illuminated emergency signage that is readily adaptable to comply with fire and building code.
A final object of the present invention is to provide a selective color LED lamp for use in newly manufactured illuminated signage with optional emergency lights integrally and operationally mounted with the main lamp unit.